Process of producing a phenolic condensation product



Dec. 22,1925. 1,566,823

C. B. CARTER PROCESS 0F PRODUCING A PHENOLIC' GONDENSATION PRODUCT Filed July 26, 1924 ,Fe/YZO?? Car/72e j. 0627 e7",

Patent 22,1t`

Canam a. cannula, or rrrrsnuncn, riannsrnvaum, n ssrenon 'ro s.

l anos., or cuIcaoo, ILLINoIs, .a ooiarorron or wasn merma.

/ PROCESS FA ti D'UCING- .A PHENOLC CONDENSATION PRODUCT.

Application mainly ae, iaaa. amai no. manca.

To all whom t may concern.'

. Be it known that I, CARNIE B. CARTER, a

citizen of the United States,y residing at Pittsburgh, in the county of Allegheny and c State of Pennsylvania, have invented a new and useful Improvement in Processes of Producing a. Phenolic Condensation Product,

of which the following is a specification.

This invent-ion relates to the production lo of phenolic condensation products; and the primary object is to provide a sim le and practical process for producing suc products by .digesting a phenolic body in an aqueous solution of hexamethylenetetramine and ammonium chloride. Such a solution may be obtained cheaply, and in a simple manner, by causing a reaction vbetween methylene chloride and aqueous ammonia; or,l it may be obtained by/dissolving a mixture of hexamethylenetetramine and ammonium chloride produced by reaction between methylene chloride and liquid ammonja.

The ,discovery that 'such a solution can be emplo ed for eecting condensation of a pheno ic body renders it possible to utilize lhexamethylenetetramine produced in the manner suggested without the necessity of eii'ecting separation of the hexamethylenete tramine from the ammonium chloride roduced by reaction between methylene c loride and ammonia.

It has been demonstrated that methylene chloride reacts with ammonia, either as liquid ammonia, or as ammonia in aqueous so ution, to form hexainethylenetetramine and ammonium chloride in accordance with the following equation:

yWhen carried out in liquid ammonia solution the reaction leads to the production of hexamethylenetetramine and ammonium chloride in theoretical proportions and the salts are present in the final product both in solution in liquid ammonia and as a crystalline precipitate. In order to make recovery of the hexamethylenetetramine from suchproducts it is only necessary to evaporate the liquid ammonia and extract the residual salts with suitable solvents, such as carbon tetrachloride or chloroform. When carried ont in aqueous ammonia solutions,

however, the reaction gives rise to an aqueous solutionl of hexamethylenetetramine and ammonia chloride from which hexamethylenetetramine cannot be recovered by simple evaporation of the water and extraction of the residual salts with chloroform or other solvents. The use of solvents to eect the extraction is expensive, moreover.

Evaporation of an aqueous solution of hexamethylenetetramine and ammonium chloride is accompanied by secondary reactions which result in the production of the hydrochloride of hexamethylenetetramine and the actual loss of some hexamethylenep tetramine through hydrolysis which permits of the escape'o free formaldehyde. -These secondary reactions may be illustrated as follows Among the various reactions which taire place on evaporating a solution containing hexameth lenetetramine and ammonium chloride, ydrochloric acid is set tree and combines with the hexamethylenetetramine in accordance with equation (3) to form the greater or less amount of hexamethylenetetramine hydrochloride. of hexamethylenetetramine actually lost to the final residue and the amountof hydrochloride formed are dependent upon conditions. taken during the evaporation to suppress the hydrolytic edectsY several per cent of the hexamethlenetetramine may escape andA practically a of the remainder may c xist in the nal residue as the hydrochloride.

The 'amounts H precautionary measures are not l This is-particularly true if the liquors resulting fromthe reaction between aqueous ammonia and methylene chloride are evaporated without taking due precautions; 80% or more of the hexamethylenetetramine in the residue from lsuch solutions cannot be extracted with chloroform or other solvents f due to the fact that it exists as the hydroy chloride.

In my application Serial No. 691,673, filed inthe United States Patent Oilice Februa 9,' 1924, I have described a method of e fecting seperation of hexamethylenetetramine and ammonium chloride from solutiony bg' evaporating-the solution in such a way t at the liquor,` at all times, is in an ammoniacal condition, drying the residual salts in the presence of ammonla gas, and finally i' extracting the hexamethylenetetramine with chloroform or other suitable solvents.

In my application Serial No. 728,463,

grams of phenol or cresol in a flask with a suiiicient quantity of the li uor\to produce a fusible, soluble resin, an heat the flask under a reflux condenser, at a temperature of about 100, for a period of from4 one to two hours. Reaction takes place readily and smoothly. The resin being heavier than .the liquor collects at the bottom of the vesfilcd of even date herewith, I have describedv another method of edectin separation which consists in surchargingt eliquor with gaseous ammonia and salting out the hexamethylenetetramine, then removing from the hexamethylenetetramine the solution of ammonium chloride, and recovering the ammoieium chloride from the solution by a method of precipitation. This last mentioned process is based on thev discoveries rami-ne an ammonium chloride.

thol and their homologs, with methylene l reacting upon'a V phenolic body, such as p enol, cresol, naphsel, and the bulk of the aqueous liquor containing the ammonium chloride can be removed by simple decantation, after which the resin can be washed by agitation or kneading with hot or cold water in order to remove all ammonium chloride. This last step is important, and the resin should be thoroughly washed and purified, but this can readily be accomplished in accordance with the present process.

The solutlon of hexamethylenetetramine and ammonium chloride preferably is obtained by introducing methylene chloride and aqueous ammonia into an autoclave, the ammoniabeing taken in excess to the extent of 300. or 400 per cent above the theoretical proportions, and heating the Iautoclave at a temperature of about 100 C. un-

til the reaction is complete.y This liquor may then be ammonia distilled oil", after which the liquor may pass to-a di ester, into which a sufcient quantity .o the phenolic body may be charged. The digester may be main tained at a suitable temperature, say at a temmrature of about 100 C. until the condensation is com leted.

Another metho of obtaining the solution of hexamethylenetetramine and ammonium chloride for use in the process is to cause a 'reaction between. methylene chloride and chloride4 and ammonia, suiicient ammonia being present in the reaction mixturer to combine with all chlorine contained in the methylene chloride. As indio'ated above, in the present process hexamethy1enetet-ramine and ammonium chloride are rst formed in solution and the liquor is utilized for digestin a phenolic body and producin the 'con ensation product. V

henol'ic bodies, such as phenol, cresol,

' etc. react readily with the hexamethylenetet-A ramine contained in the aqueous liquor ob*- tained by the action of methylene chloride Y on aqueous ammonia solutions.

* the reaction can successfully be carried out That is,

by utilizin a solution of hexamethylenetethis may be readily demonstrated by placinga few liquidl ammonia, emplo ing ammonia in large excess, d1st1ll oil" t e excess ammonia passed to a vstill and the excess v after completion4 of the reaction, and dissolve the salts in water.

In carrying out the present rocess, it is desirable to employ a considera le excess of the phenolicbody, referably about 50 per cent excess, above t at which is required to combine with the hexamethylenetetramine present in the solution to forman infusible and substantially insoluble condensation product. That is, by the resent rocess, the condensation product will rst e produced as a .distinctly fusible and soluble product. After the purification, a sufficient quantity of an active methylene body will be added to the fusibleproduct to 4produce the final infusible product.

The following example will illustrate the manner in which the fusible and soluble condensation product may be formed:

Place in 'a 100. c`e.- liask, twenty grams of phenol and 37 .5` cc. of a Iliquor containing 3.3 grams of hexamethylenetetramine and 7.2 grams of ammonium chloride; heat"1 at boiling point under a redux condensor for l f i :escasas v rllhis produces a viscous resin corresponding with resin 'produced by known processes, employing about nine mols of phenol and one mol of hexamethylenetetramine. Additional boiling would not change the character of the resin, and it thus appears that `the reaction is completed in one hour, ory

less. Such a resin is scarcely iiuid enough to be agitated with water at room temperature, but `can be kneaded between the fingers at 10 C. to 15 C., and washed with running water. be performed by agitation with hot water. The washed-resln possesses all the properties of resins made by known processes, for example, the fusible, soluble resin produced by condensing about nine mols of phenol with one mol` of hexamethylenetetramine. Such a resin possesses about one and onehalf phenolic groups to each 4methylene group.

As carried out above, the reaction mixture contained no ammonia other than that liberated' in the reaction. The reaction takes lace readily in the resence of ammonia, but in case it is carrled out under atmospheric pressure, as described above, most of the ammonia is expelled during the boiling operation.

The reaction ma be carried out in practice as follows. he henol or other henolic body is placedin a suitable stil or ldigester, equipped with a reflux condenser,

together with suf'ncient amounts of the liquor from the hexamethylenetetramine reaction to producev a fusible soluble resin of lthe desired degree of fluidity, or mobility, f'or'ease in washing; Heat is then Iapplied and .the

mixture brought to and maintained"|` at the v boil for one or two hours in order to eii'ect complete reaction. During this operation large volumes' of ammonia will be evolved.v

from the digester if the liquor has not been distilled previously in yorder to remove the excess ammonia used in the hexamethylenetetramine reaction. In event the excess has not been removed by distillation theretlux' `washed out by agitation or kneading with i water. The combined liquor and'wasl'i waterthen go to a still 'where they are treated Vwith hydrated lime to liberate ammonia from the ammonium chloride, the ammonia being absorbed in water and returned .to the hexamethylenetetramine system.

The accompanying drawing illustrates,

"'diagrammatically, suitable apparatus for At higher temperature, washing can,y

practicing the process in the referred manner, and the process may e further explained with reference thereto.

In the drawing, A represents an autoclave drawing supplies of methylene chloride and aqueous ammonia from storage tanks B and C, respectively. A mixture of these materials is heated in A until .reaction is comlete, all methylene chloride being converted 1nto hexamethylenetetramine and ammonium chloride. The contents of autoclave A then are expelled into a still D where excess arnmonia is distilled oi, the gaseous ammonia going to an absorber E, where it is taken up in water from storage F, and finally collects in storage C. The residual liquor from` still D containing hexamethylenetetramine, ammonium chloride and some small amount of free ammonia passes into digester G where it is mixed with the necessary amount of tio lphenol from P and is digested until all evolved during digestion passes through MN to absorber E and finally collects in storage C in the form of aqueous ammonia. The resin and digester liquor from G go to a washer H where the resin is agitated with water to remove all ammonium chlo ride, the resin being discharged into storage I and the aqueous ammonium chloride into still J. In still J the solution is treated with sufcient h drated lime to liberate all ammonia from t e ammonium chloride and is subjected to distillation to remove am- Inonia which passes through QN to absorber E and collects in aqueous form in C. The

residual liquor from still J carriescalcium lchloride which may be recovered byevaporationoi the water if recovery is to be made.

It is to be noted that the hexamethylenetetramine reacting with the phenol in digester G liberates ammonia. Hence it JEollows that little ammonia is actually consumed in the operation, since all ammonia 110 combining to form methylene chloride in the hexamethylenetetramine reaction is recovered by treating with lime. In operation, however, some small amount of ammonia may be carried out of the system by the resin and such ammonia must be made good by adding aqueous ammonia to the system from time to time.

It is also to be noted that phenol is to be 'taken with the hexamethylenetetramine solu- 120 tion in such proportions as to produce a resin of a iiuidity or mobility suitable for ease in' washing. A resin containing 9 to 10 mols of phenol to,6 methylene groups is suitable for the purpose. l'

The fusible resin produced in accordance with the method described above is subjected to -distillation in order to remove all water and a portion of the free henol. The distillation may be effected by oiling or by 130 blowing air through the heated resin and as much as 10% of the original phenol may be removed. The resin resulting from this treatment may be finished in the usual Way by adding an active methylene body, such as formaldehyde or. hexamethylenetetramine,

in'such proportion as to give a final massA containing about one phenol group for each methylene group, and heating to finish the reaction. Prior to the final lheating the mass may be mixedwith fillers or taken up in suitable solvents to form varnishes, Ior utilized in the various compounds for which phenolic resins 'are used.

In the drawing, additional lines of communication, or routes, between the Various vessels and devices are designated by the numerals 1 to 12 inclusive. The arrowsI inl'dicate the course followed by the products in the routmgs.

The proportions of materials employed v may be varied. For example, a smaller pro- Aa nd insoluble portion vof .phenol may bef employed, but as the. proportion of henol is reduced the resultant condensation product approaches more and more closely to the final, infusible product.

It is possi le to employ vsubstantially equi-molecular proportions of hexamethylble, in viewof the prior art.

What regard as new, and desire tov secure by Letters Patent, is:

1. The `method of producing a 'phenolic condensation product which comprises: producing hexamethylenetetramine and ammo.

' nium chloride by reaction between'methylene chloride and ammonia; digesting a phenplic body with a solution of said salts the phenolic body lbeing taken in excess of the molecular proportions with respect -to the hexamethylenetetramine formed-in the reaaeaeaa action; separating the fusible, soluble resin thus produced from the liquor; and purify# ing the resin.

2. The method .of producing a phenolic condensation product whichv comprises: digesting a phenolic body in a solution fof hexamethylenetetramine and ammonium chloride, the phenolic body bein sulicient excess with vrespect to the examethylenetetramine present in the solution to form a fusible, soluble condensation product, separating the liquor from the resin; and purifying the resin by washing with water.

3. The method of producing a phenolic condensation product which comprises: causing a reaction between methylene chloride and aqueous ammonia, the ammonia being present in excess of the theoretical requirement; distilling ofi the ammonia and returning it to the source of ammonia supply; charging the residual liquor and a phenolic body into a digester and effecting condensation of the phenolic body; separating the liquor from the condensation product; and purifying the condensation product.

4. The method of producing a phenolic condensation product which heating togethel. a phenolic body 'and a solutaken in' comprises tion of hexa'inethylenetetramine and ammo-v nium chloride; separating theI liquor from the 'condensation product thus formed; removing some of the ammonium chloride from the solution; heating together methylene chloride and some of the remaining solution in the presence of ammonia and employing the resultant liquor in the rocess to digest an additional quantity of tli) nolic body.

5. The method of producing a phenolic condensation product which comprises: heat- `ing a mixture of a phenolic body and a solution of hexamethylenetetramine and ammonium chloride, the phenolic body being taken in sufficient excess with respect to the hexamethylenetetramine present in the solution to form a fusible, soluble, condensation product; separating the liquorfrom the resin a suliicient quantity of an active'methylene body to combine with the resin and resin; purifying the resin and adding to the form a substantially infusible and insoluble product. l

. CARNIE B.- CARTER. 

